A cross between two or more unrelated parents
•The most productive innovation in plant breeding
•It started a revolution in
•Agricultural productivity
•Uniformity of products
•Fixing specific traits that serve as trade marks
•Seed production and marketing
•Catalyst for the establishment private sector
•By 1955 = 100% maize area in USA hybrid due to its better performance
•1984 spread to Europe
•1960 and 1970 in Eastern and Southern Africa
Hybrid performance and heterosis
Heterosisis expressed when two genetically unrelated parents are crossed to create a hybrid
Mid-parent heterosis(%)= [(F1-MP)/MP] x 100
High-parent heterosis(%)= [(F1-HP)/HP] x 100
•F1 = performance of the hybrid
•MP = Average performance of the parents of the hybrid
•HP = Performance of the best parent of the hybrid
Hybrid vigor: Maize lines B73 (left) and Mo17 (right) produce the hybrid F1 (center).
